Method and device for removing flat packages from a pile
AssigneeSiemens Aktiengesellschaft
InventorsFrank Gerstenberg, Hauke Luebben
Life of this patent
Estimating the term…
Abstract
The invention pertains to a method for removing flat mail pieces from a pile by means of a removal device with controllable removal velocity which feeds the mail pieces to conveyor belts driven at the velocity v0. Set velocity value profiles are associated with the differences between set and actual gaps. Since the curve forms are selectable, the drive ratios can be taken into account. The association of the set velocity value curves of the drive unit with the actual gaps in order to achieve the set gap at the takeover point of the conveyor belts at velocity v0 takes place in previous measurements. The nonlinearities of the transfer function of the drive unit are detected by tabular assignment of the velocity profiles on the basis of measurements.
Claims13
A method for removing flat items from a pile by means of a removal device with a controllable removal velocity, comprising:
- (a) feeding a first item by means of a drive unit from one end of the pile to a takeover point of a conveyor driven at a velocity v0;
- (b) feeding a second item from the one end of the pile to the conveyor when a rear edge of the first item has reached the takeover point of the conveyor;
- (c) determining an actual distance between the rear edge of the first item and a first sensor located proximate the pile at a point in time when a front edge of the second item has reached the first sensor and the second item has reached the velocity v0;
- (d) repeating steps (a) to (c) while maintaining a set distance between successive items by activating a predetermined velocity value profile for the drive unit which corresponds to the actual distance, which profile is one of a plurality of stored set velocity value profiles for the drive unit of the removal device associated with differences between the set distance and actual distances for spacing between successive items for the removal process in order to maintain the set distance between the items after intake of the items by the conveyor, wherein the velocity profiles are established as a function of transfer behavior of the drive unit and for a defined terminal velocity, and wherein times that items require in the respective set velocity profile in order for a front edge of each item to move from the first sensor to the takeover point of the conveyor are determined in prior measurements for the association of the times with the differences between the set distance and the actual distances.
A device for the removal of flat items from a pile, comprising:
- a pair of conveyor belts drivable at a constant velocity and disposed to engage a flat item on opposite sides and transport the item;
- a removal element including a drive unit for feeding flat items one at a time from one end of the pile to a takeover point of the conveyor belts;
- a stop wall that holds the pile in position relative to the removal element;
- first and second sensors for detecting the items, wherein the first sensor is located at a position between the stop wall and the takeover point at which an item being removed has reached a removal velocity v0, and wherein the second sensor is located at the takeover point of the conveyor belts;
- and
- a control system for maintaining a set distance between items by controlling item removal times and velocities as a function of the respective distance between a first item removed from the pile and a second, succeeding item removed from the pile as calculated from removal velocity v0 and a reading from the first sensor indicating that an edge of the second item has reached the first sensor.
Dependencies are inferred from the claim text.